Danish design firm Bjarke Ingels Group (BIG) has been announced as the winning team to lead the first phase of the Smithsonian Campus Master Plan, in a US$2.4m (1.85m euro, £1.59m) contract.

At 700,000sq ft (65,032sq m) the campus in Washington D.C., US is the world's largest museum and research complex and includes 19 museums, the National Zoological Park and nine research facilities.

BIG has already revealed it hopes to reinstate the Smithsonian Castle, built in 1855, as the cornerstone of the campus, serving as a welcoming point, an information hub for visitors and the symbolic home of the Smithsonian institute.

A grand entrance will connect the castle and the Central Garden to the National Mall and adjacent museums.

Founding partner of BIG Bjarke Ingels said: "The abundance of historical heritage, the diversity of architectural languages and the cacophony of exhibits are tied together by a labyrinthine network of spaces above and below ground - inside and outside.

"Our task is to explore the collections with The Smithsonian and together attempt to untie the Gordian Knot of intertwined collections to unearth the full potential of this treasure chamber of artefacts."